How to Survey Land with 18th Century Tools – The Tools

Land surveys consist of six basic tasks: Determinizing your position on Earth using celestial navigation methodsMeasuring distances with a Gunter’s Chain.Measuring changes in elevation with a Range PoleMeasurement of directions and angles using a Compass.Drawing the map on a Plane Table, andComputing areas with basic plane geometry In this series we will discuss the fundamentals …

The Surveyor’s Artificial Horizon

Much of what you read about celestial navigation is focused on ocean navigation where you have a reasonably unrestricted line of sight to the horizon. Terrestial navigators and surveyors often do not have this and must make adjustments in their technique. One very common approach is to use an ARTIFICIAL HORIZON. An “artificial horizon” is …

Colonial Surveyor – Determining your Position using Celestial Navigation

A sextant is an intimidating complex instrument.  It consists of an A-shaped frame with an apex of 60° on a sextant or 45° on an octant.  Along the rounded lower edge of the frame is an arc, the limb, that is marked with numbers for the degree of the angles that the sextant can measure. An index …

Vector Computations without the Benefit of Modern Trigonometry

Navigating from point to point is a relatively simple task for most surveyors or mariners.  You establish a compass bearing from where you are to your intended location then measure out the distance (or in the case of sailing a speed and a time) to the new location giving what we call today a vector.  …

A Short History of Mapmaking in the Americas

Maps of land surfaces and charts of the sea coasts are scaled down representations of the earth’s surface. They are ideal documents to prove that a discovery has taken place and provide the means for the exploration to be repeated by others.  They are tremendous assets to the military and are a great aid to …

Upcoming Event

“Hands on”  18th Century Surveyor class  May 29, 2021 — 11:00 am & 2:00pm (two sessions) 11:00 – 12:00             Mapping the Fort (urban surveying)Military survey of grounds inside the fortPreparation of plat plan for use by military architect1:00 – 2:00                  Wilderness Survey (beyond fort’s walls)Military survey of trail and paths to mortar casematesPreparation of surveyor’s …

Vector Computations without the Benefit of Modern Trigonometry

Navigating from point to point is a relatively simple task for most surveyors or mariners.  You establish a compass bearing from where you are to your intended location then measure out the distance (or in the case of sailing a speed and a time) to the new location giving what we call today a vector.  …